Messages in this thread | | | Date | Wed, 6 May 2015 10:30:55 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [PATCH v2 2/3] usb: xhci: implement device_suspend/device_resume entries |
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On Wed, 6 May 2015, Lu Baolu wrote:
> This patch implements device_suspend/device_resume entries for xHC driver. > device_suspend will be called when a USB device is about to suspend. It > will issue a stop endpoint command for each endpoint in this device. The > Suspend(SP) bit in the command TRB will set which will give xHC a hint > about the suspend. device_resume will be called when a USB device is just > resumed. It will ring doorbells of all endpoint unconditionally. XHC may > use these suspend/resume hints to optimize its operation. > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
...
> #else /* CONFIG_PM */ > > int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd, > @@ -4704,6 +4728,16 @@ int xhci_disable_usb3_lpm_timeout(struct usb_hcd *hcd, > { > return 0; > } > + > +void xhci_device_suspend(struct usb_hcd *hcd, > + struct usb_device *udev, pm_message_t msg) > +{ > +} > + > +void xhci_device_resume(struct usb_hcd *hcd, > + struct usb_device *udev, pm_message_t msg) > +{ > +}
You don't need to have empty functions. Just do this:
#define xhci_device_suspend NULL #define xhci_device_resume NULL
in the appropriate place, when CONFIG_PM is not enabled.
Alan Stern
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